Rubbing-machine.



G. T. JOHNSON.

RUBBING MACHINE.

APPLICATION FILED Aue.2l. 19|5.

Patented Oct. 10, 1916.

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G.T.10HNSQN. RUBBING MACHINE.

APPLICATION FILED AUG.21. 1915.

Patented Oct. 10, 1916;

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G. T. JOHNSON. RUBB|NGMACH|NE- APPLICATION FILED AUG21| 1915. 1,200,621.

Patented Oct; 10, 1916.

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STATES PATENT OFFICE.

GUSTAVE T. JOHNSON, OF BELOIT, WISCONSIN, ASSIGNOR TO P. IB. YATES MACHINE COMPANY, OF BELOIT, WISCONSIN, A CORPORATION OF WISCONSIN.

RUBBING-MACHINE.

Specication of Letters Patent.

Patented Oct. 10, 1916.

Application led August 21, 1915. Serial No. 46,616.

To all whom t may concern.'

Be it known that I, GUsTAvE T. JOHNSON, a subject of the King of Sweden, residing at. Beloit, in the county of Rock and State cf lVisconsin, have invented certain new aud useful Improvements in Rubbing-Machiles, of which the following is a specification.

yhis invention relates to machines for rubbing or polishing wood intended for use in cabinet work, furniture and the like. In the finishing of such material or the completed product it is necessary to bring the surface to a high degree of smoothness and after each successive coat of varnish has been applied and allowed to harden to rub the Surface with an abrasive material, either sand paper or finely ground pumice stone mixed with water or oil. This is done by hand or as has been proposed by means of machines especially adapted for the purpose, the rabbino' machine being placed upon the surface anc rubbing shoes or pads reciprocated by means of suitable power. An objection inherent in machines designed for this purpose has been the utilization of guiding grooves within which the rubbing shoes reciprocate, it being necessary that the rubbing surfaces of the shoe move in a right line over the surface to be treated. The

abradant material used in the polishing of In order that the invention may be readilyy understood a preferred embodiment of the same is set forth in the accompanying drawings and in the description based thereon.

The invention being susceptible of embodiment in varied constructional forms without departure from the principles of the same as above outlined the drawing and description are to be taken in an illustrative and not in an Aunnecessarily limiting sense.

In the drawings Figure 1 is a side elevation of the improved rubbing machine, one side of the casing being removed to afford a View of the interior; Fig. 2 is a horizontal section on the line 2 2 of Fig. 1; Fig. 3 y1s a transverse vertical section on the line of Fig. 1; Fig. 4 is a longitudinal vertical section through one end of the machine taken on the line 4-*4 of Fig. 5; and Fig. 5 is a horizontal section taken below the machine frame and showing in top plan view one of the rubbing shoes.

As herein illustrated, the frame of the machine is indicated generally at 11 as provlded at each end with a handle 12 whereby the same may be moved as required from one part of the work surface t0 another, sald frame being surmounted by a motor casing 13. By 'means of the motor shaft 14 power is transmitted through the worm 15 to the worm wheel 16 upon the Shaft 17 which shaft likewise has keyed thereon a spur gear 18 meshing with a companion gear 19 upon the crank shaft 20, the shafts 17 and 18 being suitably journaled in side supports within the machine frame.

At each end of the machine is arranged a pair of posts 21, 22 which respectively serve as pivotal mountings for the members of a pairof upstanding links 23, 24. These links extend upwardly at a converging in clination to each other and have their upper free ends pivoted at 25, 26 to the opposite Sides of the head of a Twshaped or triangular link 27 which depends vertically through the bottom of the machine .frame and has pivoted thereto at 28 a rubbing shoe 29. At the point 30 intermediate its length the link 27 is pivoted to a crank arm 31 driven from the crank shaft 20.

Each of the rubbing shoes 29 comprises a body portion which may be open above and has a beveled end surface 32 and a flat bottom surface 33. Cam or eccentric pins 34 extend transversely of the shoe, being suitably journaled in the side walls thereof and each provided with a hand lever 35 equipped with a finger piece 36 by means of which said eccentric pin may be rocked, a stop 37' being provided to limit the movement of the lever in one direction. The cam or eccentric portions 38 of the pins 34 are journaled Within the heads 39 of the bolts40 which extend in opposite directions through the end wall of the shoe and have mounted on their outer extremities beveled clamping cli s 41 held in adjusted relation upon said bo t by means of the nuts 42.

It will be clear that a pad 43 ofsand paper, or of other material suitable for the purpose Where pumice stone' or oil is to be used, may be stretched over the bottom face of the shoe with its ends extending upward along the beveled ends of the shoe and clamped in place by operating the lever 35 to turn the eccentric pin 34 and thus draw the clamp 41 firmly a ainst the same. The pad may be removed or renewal or change with equal facility, releasing the clamps 41 by a reversal of .the movements just indicated.

It will be readily seen that the peculiar mounting of the shoes causes the pivot 28 thereof to move in a right line beneath 'the machine frame and without the necessity of using any guides to confine its movement, by reason of the fact that the links 23, 24 are arranged at such an inclination to each other that as the crank arm 31 moves to the right, for instance, havin reference to the left hand end of Fig. 1, t e pivot 25 moves in a descending arc while the pivot 26 moves in an ascending `arc about their respective pivots in the posts 21, 22 and as a resultant the pivot 28 neither rises nor falls but moves in a straight horizontal line. It is thus made possible to mount the shoe 29loosely for rocking movement about its pivot 28 with the result that it moves freely back and forth over the surface to be finished without jar or vertical vibration.

The link 27 is lloosely confined between the vertical walls 'of the members 44, 45 of the machine frame but this has no function in guiding the rubbing shoes in a horizontal ath, serving only to relieve the links 27 rom any bending moment in the shifting Vof the machine laterally by means of the handles 12 to brin the machine above a new portion of the sur ace being treated. I claim': 1. In a rubbing machine, the combination with a supporting frame, a rubbing shoe pivoted thereto to rock freely thereon and means inde endent of guides for confining the pivot o the shoe to movement in a horizontal right line.

v 2. In a rubbing machine, the combination with a supporting frame, a pair of links ivoted thereon at an inclination to each ot er, a third link pivotally connected4 to the free ends of the pair of links, a rubbing shoe carried by the third link, and means to reciprocate the shoe in a horizontal right line independent of guides.

3. In a rubbing machine, the combination with .a supporting frame, two links pivoted at one end to the frame and arranged at an inclination to each other, the third link pivoted at separated points to the free ends of the two links, a rubbing shoe mounted on the third link, and a driving member connected with the third link intermediate its connection `with the first two links and with the shoe.

4. In a rubbing machine, the combination with a supporting frame, two links pivoted at one end to the frame and upstanding at an inclination to each other, the third link pivoted at separated points to the free ends of the two links and dependent therefrom, a rubbing shoe pivotally mounted on the free end of the third link, and a driving member connected to the third link intermediate its ends.

5. In a rubbing machine, the combination with a supporting frame, two links pivoted at one end to the frame and upstanding at a converging inclination to each other, a third link pivoted at separated points to the free ends of the two links and depending therebetween, a rubbin shoe pivotally mounted at its longitudina center on the lower end of the third link, and a reciprocatory driving member connected to the third link intermediate its ends.

GUSTAVE T. JOHNSON.

Witnesses:

F. A. HORSTMANN, ROY J. ToMrmNs. 

